No Communication On Class II Data Link (BCM And SDM)

Diagnostic Chart:

Schematic:

If communications cannot be established with any modules, (BCM, PCM, SDM, or EBTCM) the fault is related to the Class II link. Types of faults that will affect communications could be a short-to-ground, short-to-voltage and an open circuit between Data Link Connector (DLC) and BCM. Internal controller faults could also cause communications errors on the data link. Since the Class II link is wired in a ring configuration, an open circuit, except between DLC and BCM, will not affect communications with BCM.